For many patients with hearing impairments, there are several types of implantable hearing devices, such as middle and inner ear implants, that can restore a sense of partial or full hearing. For example, cochlear implants can restore some sense of hearing by direct electrical stimulation of the neural tissue of the cochlea. The cochlear implant typically includes an electrode having an electrode array which is threaded into the cochlea. The electrode array usually includes multiple electrode contacts on its surface that electrically stimulate auditory nerve tissue with small currents delivered by the contacts distributed along the electrode array. These contacts are typically located toward the end of the electrode and are in electrical communication with an electronics module that produces an electrical stimulation signal for the implanted electrode to stimulate the cochlea. In another example, a conventional hearing aid may be used to provide acoustic stimulation to the auditory system in the form of amplified sound when the impairment is related to the operation of the middle ear. In addition, groups of auditory nerve axons may be stimulated with an electrode placed within the modiolus, or auditory structures in the brain may be stimulated with an electrode placed on or within the structures, for example, on or within the cochlear nucleus.
As with many implantable hearing devices, it is desirable to know the device configuration that would best suit a patient's anatomical and hearing needs before implantation of the hearing device. Currently, a surgeon rather blindly selects the cochlear electrode configuration based on subjective judgment and experience with patients in general, rather than based on objective data of the actual patient's hearing impairment and hearing anatomy. This can sometimes result in the selection of a hearing device that does not fit the patient correctly, is not implanted in the proper location, or is unsuitable in other ways.